Telegraphy



Jan. 26 1926. 1,570,877

' I. CONNELL, JR

TELEGRAPHY Filed Dec. 2, 1921 $04 4/ 7 Jaw/172w.-

L. CONNELL, JR

TELEGRAPHY' Filed Dec. 2. 1921,

'r Sheets-Swat 5 i i r v\mr LE '\N vuQ PR v g 5 1,570,877 L. CONNELL, JR

TELEGRAPHY Filed Dec. 2. 1921 7 sheetsfiheet '6 Jan. 26 1926.

Patented Jan. 26, 1926.

LAWRENCE GONNELL, 3B, OF PQRTLAND, OREGON.

TELEGRAI-HY.

Application filed December 2, 1321.

T 0 aZZ whom it may concern.

Be it known that I, LAWRENCE CONNELL, Jr., a citizen of the United States, and a resident of the city of Portland, county of Multnomah, and State of Oregon, have invented a'certain new and useful Improvement in Telegraphy, of which the following is a specification.

The object of my invention is to provide a method and means which will facilitate the sending of messages by tclegraphy.

I attain this end through providing a system of signals each composed of two or more elements, preferably using the smaller number, in which each element occurs but once in a signal. Each element in a signal is composed of one or more units of predetermined length and each signal is formed and determined by the relative lengths, or by the relative lengths and se quence, of the elements composing the signal. 1 also provide means whereby the transmission of my signals can be expedited.

As is understood by all those versed in the art, telegraphy has been hampered by such factors as retardation, inertia of the repeating and receiving apparatus and other physical properties, which slow up the transmission.

Some of the benefits of my invention are:

First, it provides codes of shorter average signal lengths Second, it reduces the losses from channel retardation.

Third, it reduces the losses from inertia of main line apparatus.

Fourth, it provides a system especially adapted to the use of all-electrical apparalu's for the attainment of maximum speed in the selection and recording of printed characters.

Fifth, it provides a system adapted to greater range'of circuit variation, and to new classes ofv operation as well as to the present classes, both manual and automatic.

To explain more fully, under the above headings:

First. Incomparing the average signals of my codes with those of the commonly used codes,"Morse, Continental and Baudot, it is necessary to consider the average signal used in the transmission of'a comparatively large number of characters, as in my codes together with Morse and Continental, advantage can be taken of character frequency by assigning the shorter signals to the more Serial No. 519,433.

frequently used characters, while in Baudot the signals are all of five units length. F or instance, while the average signal of the thirty-six signals making up the Morse alphabet is approximately 10.86 units in length and the average signal of the thirty- SIX signals of the Continental alphabet is approximately 12.4?" units in length, it has been found from studies which have-been made that the average Morse combination used in the actual transmission of com mercial telegrams is approximately 8 units, and that in Continental 9 units; in other words, character frequency reduces the average signal of the Morse alphabet approximately 26.3% per cent and that of the Coniinental alphabet approximately 27.84 per cent.

The length of the average signal of the thirty sir: shortest signals of my two element alphabet, when the alphabet is extended to forty nine characters by utilizing ele ments up to seven units in length, is 6.722 units. Reducing this figure by the percentage used in the Morse reduction gives approximately units, while reducing it by the percentage used in the Continental reduction gives approximately 4.85 units for the average signal combination of my two element code under working conditions. Likewise, the average signal of the thirty six characters shown in my three element code is 4.166 units in length and reducing this gives 3.06 units and 3.01 units, respectively, as the average signal combination according to the Morseand Continental reductions.

In comiiiaring with Baudot, it must be taken into consideration that the use of Baudot in this country is practically confined to printer operation and that its alphabet is not complete, there being only thirty two available signals. *Xcept in multiple operation it has been found necessary to use additional units in the transmission of each signal to care for apparatus functions, etc, and in any printer operation the incompleteness of the alphabet nenecessitates the use of upper and lower case characters, making it necessary to transmit three signals for each upper case character that occurs between two lower case characters.

It is obvious that no comparison of these codes could be absolutely exact and that the recognized average signal lengths of the I commonly used codes are only approximate.

Considering these points, a very generous comparison in favor of the commonly used codes would be: Continental 9 units, Morse 8 units, Baudot, except in multiplex opera tion, 8 units, Baudot, in multiplex operation, 5 units plus, my two element code 5 units minus, my three element code 3 units plus.

Second. The majority of circuits, as at present operated, are retarded by the inducta-nce and electrostatic capacity of the main circuits and included apparatus to a degree that keeps the speed of signalling conside ably below the capacity of the operators when manual operation is employed; and printer operation is practicable over only comparatively non-retarded circuits. The manifestation of these retarding factors is to prolong the time during which it is necessary to apply an electrical change at the home end of a circuit to induce the required resultant electrical change at its distant end, and to cause the delayed appearance of current at the distant end to occur as a gradual rise or fall as compared with the abrupt application at the home end. In other words, retardation prolongs the time necessary to complete an electrical change in a. circuit; and it is principally the eltects of retardation upon the code and system used that limits the practical length of circuits.

The commonly used systen'is sutler excessively from retardation because their nals cause a maximum of electrical changes in the channels. Some of their signals cause actual changes at the rate of one for each unit of which the signal is composed, and the others that do not cause the actual number of changes corresponding to the number of units in the signal, do cause changes at the same rate of speed as the length of the basic units of the signals is the same in all the signals of an alphabet under a. given rate of operation. Therefore, from the standpoint of retardation and average signal length. the average signal of Morse, Continenta and Baudot (except in multipl' operation) may be considered as of approximately 8 units length and as causing electrical changes in the channel at the rate oi 8 per signal. The loss from retardation is consequently approximately eight times the l ss incident to one electrical change in the channel.

My system reduces the retardation loss to a minimum by causing only one electrical change for each element of which a signal is composed. Thus. my two element code causes only two electrical changes per signal, and the less per signal is only two times the loss to one electrical change in the chan nel. instead of eight times as in the commonly rsed codes. My sending apparatus automatically lengthens each element the desired degree to compensate for retardation and the receiving apparatus discards the additions from the signals. It is obvious that the signals of my codes which are made up of elements each composed of several units could be transmitted over circuits of moderate retardation without any lengthening of the elements; but the signals which have elements of only one or two units must be lengthened for transmission over such circuits, which necessitates the lengthening of all the signals in the alphabet a corres1;)onding degree.

To explain more fully the comparative effects of retardation I will assume the transmission of the average signal of the commonly used codes and the average signal of my two element code over three classes of circuits, the first being a circuit of no appreciable retardation over which an electrical change can be accomplished in one unit of time, the second a circuit of moderate retardation over which the electrical change consumes two units of time and the third a circuit of greater retardation over which the electrical change consumes three units of time. The transmission oi the average signal of the coinn'ionly used codes would consume approximately eight units of time over the lirst circuit, approximately sixteen units of time over the second circuit and approximately twenty four units of time over the third circuit, as each unit of the signal can be transmitted no faster than the time required to complete one electrical change in these respective circuits. The transmission of the average signal of my two element code would be accomplished over the first circuit in approxin'iately five units of time, over the second circuit in approximately seven units of time and over the third circuit in approximately nine units of time, each element being lengthened one unit for transmission over the second circuit and two units for transmission over the third circuit.

Third. The current strength available in main circuits is very limited, which causes a loss from inertia due to moving the armatures of the receiving and repeat' ing relays that are energized by the main circuits from positions of rest by a feeble force. In the commonly used systems these main line instruments are either required to cooperate directly with the units of the signals, or else to operate at the same rate of speed and the length of each unit of the signal must accordingly be increased to overcome this loss the same as for channel retardation. In my system the unit operation is accomplished in the local circuits of the receiving apparatus, where comparative- 1y unlimited current strength is available to force the movement of armatures and where the apparatus can be better designed iorspeeol. at the. GXPBDSBnOf wasted .current strength. 1' I overcome this inertia loss by the same means that I use. to overcome retardation, that is, each element of my. signals may be len thened, thereby. allowing the line instruments to operate at lower speed, while the local instruments of the receiving apparatus may continue to operate at maximum speed, merely discarding the additions from the signals Fourth. It is well known that the selection and recording of signals in the present automatic printer systems is limited in speed considerably below the speed at which the signals can be transmitted. The fault lies in the construction of the codes employed which necessitate, in addition to a primary reception of the signals by fast line controlled relays or similar apparatus, a secondary mechanical selection of the characters represented that is comparatively slow and lags behind the primary selection. The cons'tructionof my codes make them especi ally adapted to the attainment of high speed in selecting and recording, principally due to the factthat the units of each element follow each other consecutively and are or". the same length, thereby permitting the selection tobe made entirely by primary and positive actions in'whichall the movements are similar and of -minimum distance of travel. For instance, the selection of type writer HIHtSln my two element printer system is efiected by disintegrating the continaiouspulse that represents an element of a signal into as many pulses of local current as there are units in; the element; and by requiringeach'of these resultant pulses merely to move thefarmature of arelay from one of its stops to; the otherto accomplish 'theiselection No; secondary mechanical selection is'necessary; It is evidentthat such primary and positive movements, forced by ample lo'cal' energy, can be accompllshed at greater speed than that at which the units of a signal can be transmitted over a main channel. "I have d'eslgned my apparatus to be practlcally all-electrical and have re duced mechanicalmovements to a minimum.

This feature of my invention will be apparent from the description of the apparatus.

FifthrThe present systems are limited in' respect to the classes of operation to which they are applicable and the'range of circuitvariationover which they are efficient.

paratus will indicate; "By reason-of the shortness ol its signals it is adapted to fast transmission over good circuits; and by reason of its comparative immunity from the effects-of retardation it is not only adapted to faster and more eiiicient work on the more heavily retarded circuits now in use, but also on circuits of greater length than can beetliciently operated by the present systems. My three element system (which utilizes a combination of elements that has always existed in polar duplex operation but which the present systems have been unable to make use of on account of the mixed order of occurrence of the elements composing their signals) is an example of the adaptability oi my invention to new methods of operation. The extreme shortness of the average signal of this code adapts it to the attainment of much greater speed than any of the systems now in use, particularly over first class circuits.

The application of my invention to the common forms'of telegraphy, printen multiplex and manual and *to a new three elep ment system, is shown in the accompanying diagrammatic drawings, of which Fig. 1 shows thirty six signals ot a two element code, in unit of length form;

Fig.2 shows the same code and signals in unit of dot form;-

Fig. 3- shows a section of tape with the same signals perforated therein, to be used in connection with my two element transmitter;

Fig. a shows a three element code;

Fig. 5 shows a section of tape to be used in connection with my two element transnutter;

Figs. 6 and 6 show a keyboard operated perforator for preparing the tape shown in Fig. 7 shows a transmitting apparatus for a two element-printer system.

Fig. 8 shows a receiving apparatus for a two element printer system;

Fig. 9. shows modified apparatus adapted for using my two element system adapted .to multiplex operation; 3

Fig; 10 shows a modified transmitting apparatus especially adapted to use my three element system;

Figs. ll and 11 show a modified receiving apparatus especially adapted to use my three clement system; and

Fig. 12 shows a two element system for manual operation.

Describing first the code shown in Fig. 1:

The heavy horizontal lines, as a, designate continuous pulses of mark current and the lighter horizontal lines, as I), designate continuous pulses of space current. The spaces between the vertical lines represent units of length. Thus, the first signal at the top, 0, is made up of a mark pulse one unit in length, followed by a space pulse one unit in length; and the bottom signal, (Z, is composed of a mark pulse six units in length, followed by a space pulse six units in length.

Describing next the code shown in Fig.

In this code the continuous pulses shown in Fig. 1 are merely broken up into the number of dots that could be made at a predetermined rate of speed during the duration of the continuous pulses. The signals are arranged in the same order as those in Fig. 1, the vertical line a dividing the mark dots from the space dots. Thus, the first signal 1) represents one mark dot, followed by one space dot, and the last signal 0 represents six mark dots, followed by six space dots.

Describing next the tape shown in Fig. 3:

The vertical row of holes at, extending up the center of the tape, designates feed holes, to be engaged by the teeth of a sprocket wheel for the purpose of feeding the tape throughthe transmitter. The perforations to the left of the row of feed holes, as 7), designate mark perforations and those to the right, as c, designate space perforations. The number of dots, or units, in the mark pulse of each signal is read by its distance to the left of the row of feed holes, and the number in the space pulse is read by its distance to the right of the feed holes, the unit of measurement being the space between the vertical lines. Thus, the first signal at the top is shown to consist of one mark dot, by perforation 6, and one space dot, by perforation 0; these perforations being one unit distant to the left and right, respectively, of feed hole (Z. The last signal designates six mark dots by perforation 6 being positioned six units to the left of feed hole f, and six space dots by perforation g being positioned six units to the right of the same feed hole.

Describing next the code shown in Fig. 4;

The heavy horizontal lines, as a, designate the first element, such as positive; the lighter horizontal lines, as b, designate the second element, such as negative, and the crossed horizontal lines, as c, designate the third element, such as zero. The spaces between the vertical lines designate units of time. Thus, the first signal at the top consists of one unit of the first element, followed by one unit of the third element, and the last signal consist-s of one unit of the second element, followed by three units of the first element, followed by one unit of the third element. All the signals end with one or more units of the third element.

Describing next the perforated tape shown in Fig. 5:

The perforations in the vertical row a designate feed holes; those in the vertical row b represent the first element perforations; those in the vertical row 0 represent the second element perforations, and those in the vertical row cl represent the third element perforations. The number of units of each element in the signals are read by the number of horizontal lines, representing units of time, between the perforation indicating one of the elements and the next perforation below, representing another element. Thus, the first signal at the top, represents one unit of the first element, followed by one unit of the third element. The second signal commences with the perforation 6 and represents one unit of the first element, followed by two units of the third element; there being two horizontal lines between the perforation f which represents the con'nnencement of the third element, and the perforation g which represents the end of the third element and the commencement of the next signal. The third signal, which starts with the perforation 9, represents one unit of thefirst element, followed by one unit of the second element, followed by one unit of the third element.

Describing next the apparatus shown in Figs. 6 and 6:

Fig. 6 designates a key board and key levers as of an ordinary typewriter, looking at it from above, of which 6 and c are two complete key levers, pivoted at d and 6 respectively. The other key levers are shown broken off near the letter caps, as indicated at P, but are assumed to be arranged similarly to levers b and 0 9 It, 2' 7' Z m 91 ,0 p and r designate twelve contact levers, pivoted at 8 t u, v Q02, :2 i e 22, 23, 24 and 25, respectively, extending beneath the key levers at right angles thereto and each adapted to make an electrical contact at its free end when forced downward by one of the key levers. 26 designates a stop against which the contact levers normally bear upward under the force of springs (not shown), the upper surface of the contact levers being thus normally held a short distance below the bottom of the key levers.

Referring to Fig. 6

27 designates an edge view of the apparatus shown in Fig. 6, of which 28 is a key lever pivoted at 29, normally held against stop 210 by spring 211 and carrying projecting knobs 212 and 213 on its lower edge. 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224 and 225 are the free ends of the twelve contact levers shown in. a electrically connected; and 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236 and 237 are their associated contact points, respectively.

280 designates a tape perforator comprising mark perforating needles 238, 239, 240, 241, 242 and 243 and space perforating the needles 244, 245, 246, 247, 24s and 249, all

held in the slotted form 250 and each having a spring, as 251 of mark needle 243, which normallyhold"the needles away from the tape; feed hole perforating needle 252 and die 253. The tape, a section of which is shown at 254, is fed forward between the die and the perforating needles by mechanism not shown.

Each perforating needle is operated by an individual electromagnetic hammer device, all of which are similar and maybe described by referring to device 255 which controls mark needle 238. It comprises ele'ctromagnet 256, armature 257, spring 258 and back stop 259. When m et 256 is- (Lbn energized armature 257 is drawn toward it and strikes against needle 238, forcing the latter through the tape. l/Vhen magnet is deenergized armature 257 is pulled back against stop 259 by spring 258, which allows perforating needle 238 to disengage the tape and resume its normal position as shown in the drawing.

The operation is as follows:

When key lever 28 of keyboard 27 is depressed knobs 212 and 213 engage cont-act levers 219 and 221 and force the latter down against contacts 231 and 233, respectively. This energizes hammer device 255 through the local circuit comprising battery 260, conductor 261, contact lever 219, contact 231, conductor 262, the coil of magnet 256, conductors 263 and 264:, the coil of magnet 265 and conductor 266, and simultaneously energiz es'hammer device 267 through the same local circuit and also hammer device 268 through the local circuit ccn'iprising battery 260, conductor 261, contact lever 2 1, contact 233. conduct-or 269, the coil of magnet 270, conductors 271 and 272, resistance 2 3 and conductor 266. Mark needle 238, space needle 24:5 and feed hole needle 252 are accordingly driven through the tape, simultaneously. The signal punched represents one mark and two space units. When key lever 28 is released the hammer devices are deenergized and allow the perforating needles to disengage the tape as explained, and

tape is then moved forward a predetermined distance for the next signal by mechanism (not shown) such as is used to feed the ribbon of a typewriter.

The remaining key levers select the desired mark and space perforating needles in the same manner, each key lever having two knobs on its lower edge positioned to engage the particular contact levers that con trol the hammer device associated with the particular mark and space needles that the key lever is designed to select.

Thus, the key lever representing the signal composed of six mark units and one space unit would have a knob directly abore the Contact lever 214, instead of in the position of knob 212 in the drawing, and a knob above contact lever 220 instead of in the position of knob 213 in the drawing; and when depressed, such a key lever would select hammer devices 274, 275 and 267,

thereby operating mark needle 243 repre-' To punch feed holes only, a key is pro-- vided having only one projecting knob on its lower edge, positioned to engage a thirteenth con-tact lever, as 276 of keyboard 27. Vl hen this key is depressed, the-local circuit comprising battery 260, conductor 261, contact lever 276, contact 277, conductor 278, resistance 279, conductor 26 1, the coil of magnet 265 and conductor 266 is closed and hammer device 267 alone is energized and operates feed hole perforating needle 252. The mechanism for moving the tape forward operates when feed holes are being punched, the same as when signals are punched.

Describing next the apparatus shown in Fig. 7:

a designates a vibrator comprising stationary support 5 in which vibrating spring c is rigidly held; vibrating rod d attached to the free end of spring 0 and carrying spring contact 6 and slidable weight 7'; and contact 9 with which spring 6 makes contact once every cycle of vibration and thereby energizes vibrator magnet h through the local circuit comprising battery i conductor y' vibrator (1 contact g conductors and Z the coil of magnet m conductors n and 0 resistance 79 and conductors g and T The ohmic resistance of the resistance 3 and the coils of the magnets 3 and 3 and the conductor 3" is of such value that the current divides and some flows thru the circuit previously mentioned and the remainder passes from the conductor 3 thru the conductor 3 armature 3, conductor 3 and resistance 3 The pull of this magnet on vibrator rod (Z at the proper point in its swing imparts the necessary additional energy to the vibrator to maintain its vibrations in the well understood manner.

.9 designates a pulse regulating rela the coil of whose magnet m is included in the above described circuit of the coil of vibrator magnet h When the circuit is energized, armature 15 engages front contact u thereby closing the shunt circuit comprising conductor :0 contact a armature t and conductor 3 across the battery leads k and 7", which supply the vibrator battery current to the apparatus yet to be described.

lVhen magnet m is deenergized, armature t engages back contact 72 under the pull of springin and a similar shunt circuit is closed, conductor 2 and contact merely being substituted for conductor and contact 27 This relay allows the vibrator battery current to flow to the apparatus yet to be described only when its armature 25 is between stops and is moving from back contact e to front contact u No current flows when this armature moves back to contact 71 because this movement occurs while the circuit is open at contact 9 of vibrator a 32 designates a group of differentially wound polarized relays, connected in multiple across the vibrator battery leads and 1, as follows: relay 33 through c0n ductor 312, coil 311 and conductor 310; relay 3 1 through conductor 313, coil 31 1, conductor 315, contact 316 and armature 317 of relay 33 and conductor 318; relay 35 through conductor 319, coil 320, conductor 321, contact 322, armature 323 and conductor 32 1; relay 36 through conductor 325, coil 326, conductor 327, contact 328, armature 329 and conductor 330; relay 37 through conductor 331, coil 332, conductor 333, contact 33%, armature 335 and conductor 336; relay 38 through conductor 337, coil 338, conductor 339, contact 3 10, armature 3 11 and conductor 342, and relay 39 through conductor 3&3, coil 344, conductor 3 15, contact 3&6, armature 3417 and conductor 3 18. The circuits that connect the above mentioned coils of relays 34: 35, 36, 37, 38 d 39 with vibrator batterv leads k and r are thus normally open until the armature of the next relay to the left engages its right hand contact, while the coil 311 of relay 33 is always on a closed circuit across these leads. The effect of these coils, when energized, is to move their respective armatures to the right. The relays are arranged, so that their armatures will remain against either stop when the relays are not energized, and the distance of armature travel between front and back stops is regulated so that any one pulse transmitted by vibrator (r and shortened by pulse regulator s will be sufficientonly to move the armature of any one of these relays from its back contact to its front contact, and not leave any lapover of current to effect the next relay to the right through the circuit closed by such a movement of one of these armatures. Hence, relay 33 will set, or move its armature to the right, on the first pulse of current transmitted by vibrator a and relay 3% will act likewise on the second pulse, relay 35 on the third pulse, relay 36 on the fourth pulse, relay 37 on the fifth pulse, relays 38 on the sixth pulse and relay 39 on the seventh pulse.

319 designates a si selecting apparatus,

which automatically handles the perforated tape shown in Fig. 3, and selects the signals by the perforations therein. 350 represents a cross section of tape cut across the perforations comprising one signal. The tape is shown as travelling upward through the plane of the drawing, and perpendicular thereto. 351 represents the mark perforation, 352 the feed hole perforation and 353 the space perforation. 354, 355, 356, 357, and 359 and the sixth, fifth, fourth, third, second and first mark selecting needles, respectively, held in a slotted form (not shown) beneath the tape, so that their upper tips are directly beneath the pointsin the tape where the perforations should occur that represent the sixth, fifth, fourth, third, second and first mark units, respectively, when the tape is in position to register a signal. 365, 366, 367, 368, 369 and 370 represent the first, second, third, fourth, fifth and sixth space selecting needles, respectively, which are likewise positioned beneath the tape where the first, second, third, fourth, fifth and sixth space perforations, respectively, should occur. The six mark needles are electrically connected with each other, as indicated at 360, and the six space needles are likewise connected. The needles are otherwise similar, each having a projecting knob, as 361 of needle 3541:; a contact making extcnsion at its lower end, as 362 of the same needle; a contact point assoc'ated therewith, as 363 of the same needle, and a compression spring underneath its lower end to force the needle upward into engagement with its associated contact point, when the needle is otherwise free to rise, as 364 of the same needle. 371 and 372 are two needle controlling levers, operable between stops 373 and 374-, and 375 and 376. respertivcly, by the pull of magnet 377 against spring 378 and the pull of magnet 379 against spring 380 respectively. Magnet 377 is energized and holds lever 371 down during the time mag net 379 is deenergized and lever 372 accordingly pulled up against its upper stop 375 by spring 380, and vice versa, through the two local circuits, the first comprising battery 381, armature 382, contai-t 383, conductor 38-1, the coil of magnet 377 and con ductors 385 and 386 and the second comprising battery 381, armature 382, contact 387, conductor 388, the coil of magnet 37.) and conductors 389 and 386: these respective circuits being active and inactive accordingly as armature 382 engages one or the other of its contacts 383 and 387. When either lever down, the needles controlled by it are prevented from rising by the lv'obs. as 361 of needle 35%, engaging the bottom of the lever. lVheu either lever is up the needles controlled by it are free to rise if a perforation occurs above them, as indicated by space needle 370 which is shown projectii'ig Ill amar? '7 throughspace perforation 353m the tape; and the needle that are positioned below the unperforated portion of the tape are held down by the tape itself. The contact points associated with each mark needle is electrically connected with the contact associated with the corresponding space needle, as *1- dicated by conductor 390 joining the contact points associated with the first mark a 1 first space needles, conductor 391 joining the contact points associated with the seco d mark and space needles, conductor 392 join ing the contact points associated with the third mark and spaceneedles, conductor joining the contact points associated with the fourth mark and spate needles, conductor 39% joining the contact points assochited with the fifth mark and space needles and conductor 395 joining the contact points associated with the sixth mark and space needles. Each pair of contacts thus joined is connected with one of the timing relays, as indicated by the extension of conductor 390 to contact 322 of timing relay 3%; conductor 391 to contact 328 of relay conductor 392 to contact 334 of relay 36; conductor 393 to contact 3l0 of relay 3? conductor 394 to contact 3&6 of relay 33, and conductor 395 to contact 396 of relay 39. This connects any needle that engages its associated contact point with the vibrator battery lead r through the armature and right hand contact point of the timing re with which it is connected, when the ture of that particular relay engage its right hand contact. 397 is an end view of the sprocket wheel, the teeth of whicl'i engage the feed holes'in the tape and move the tape forward the distance of one feed hole at a time, in the well understood manner.

398 and 399 are differentially wound po larized relays, one coil of each being connected with the mark needles through conductor 3100, coil 3101 of relay 399, conductor 3102 and coil 3103 of relay 393. l he other coil of each relay is connected with the space needles through conductor 31. coil 3105 of relay 399, conductor 3106 an coil 3107 of relay 398. The windings disposed to move the a matures of these relays in the direction indicated by the a ows on the coils. Relay 399 is the line transmitter proper, by means of which the si ;nals are applied to the line; and relay 39h controls the needle controlling levers through the local circuits already described.

3111 designates a reset relay, compri armature 3112, having spring contact 11 at its upper end; spring 3114; front 1 back stops 3115 and 3116, respectivelv: con tact point 311'? and magnet 31.18.

The (3011 of the latter is included in the circuit connecting relay 398 with battery lead 72 comprising conductor 3119 which connects with both coils of relay 398 at the point 3120, the winding of magnet 3118, and con ductor 3121. The contact 3117 a'ndspring contact 3113 of relay 3111 control the ie set coils of the timing relays through the local circuit comprising battery 3122, corductor 3123, coil 312d of relay cmiduclzor 3125, coil 3126 of relay 38, conductor 312?, coil 3128 of relay 37, conductor 3129, coil 3130 of relay 36, conductor 3131, coil 3132 of relay 35, conductor 3133, coil3l3l of relay 34., conductor 3135, coil of. relay 33, conductor 3137, armature 3112 of reset relay 3111, spring contact 3113, contact point 311? and conductor 3138.

The operation of the apparatus c nstr and arranged as described is as follows:

The various parts are shown in the drawing as they should be at the commencement of the transmission of the space pu so of :2 signal. The transi'nission of the mark pulse has just been completed. Space needle 1 is in contact with its associated contact point, its upper end projecting through space perforation 353 which designates six units as the length of the space pulse to be transmitted. The other space needles are held down by the unperforated portion of the tape and the mark needles are held down by needle controlling lever 371.

The first pulse of current transmitted by Vibrator a and shortened by pulse regulating relay 8 will pass through the coil 311 of timing relay 33 and cause that relay to move its armature 31'? to the right and e11- gage contact 316, which closes the circuit connecting the coil 31 1 of relay 31- across the battery leads r and 76 but just too late to be energized by the pulse that moves the armature of relay 33. Relay 3 1 will then set on the second pulse, relay on the third pulse, relay 36 on the fourth pulse, relay 3? on the fifth pulse and relay 33 on the sixth pulse. The seventh pulse will likewise set the armature of relay 39 into contact with point 396, which will close across the leads 76 and r, the circuit comprising the armature of relay 39, contact coir ductor 395, the contact point associated with space needle 370, space needle 3T0, conduc- N tor 310-1, cell 3105 of relay 399. conductor 3106, coil 310'! of relay 398, conductor 3119. the coil of magnet 3118 of reset relay 3111 and conductor 3121; but no current will flow through this circuit on the seventh pulse for the same reasons that govern the setting of the timing relays.

The eighth pulse will energize this circuit and cause the line transmitter 399 to move its armature to contact 3109. needle regulating relay 398 to more its armature to contact 387 and reset relay 3111 to close momentarily against contact 311, and then resume its open position. The results of these actionswill be as follows: Linc transmitter relay 399 will terminate the application of the space electrical element to the line and will apply the mark electrical element in its stead; reset relay 3111 will put a momentary pulse of current from the reset battery 3122 through the reset coils of all the timing relays and cause them to move their armatures into the reset positions, against their left hand stops; needle controlling relay 398 will open the local circuit of magnet 377, thereby causing needle controlling lever 371 to move up against stop 373 and liberate the mark needles to rise and engage the tape, and will close the local circuit of magnet 379 thereby causing the needle controlling lever 372 to be drawn down against stop 376, which will force the space needles downward out of engagement with the tape and move the tape forward to the next signal by turning the sprocket wheel 397 forward one tooths distance, as explained.

It is evident that two extra units were added to the space pulse of the signal that was transmitted as described, as the tape indicates a six unit pu'lse, while eight pulses of the vibrator current were consumed in registering it. These two added units represent the lengthening of the pulse sent through the channel of communication to compensate for the retardation losses therein. If such lengthening of signals is not desired, the timing relays 33 and 34 can be made inoperative by screwing the contact points against their armatures so that these armatures are held firmly against their right hand contacts. The first pulse of the vibrator current will then operate relay 35 and, if the signal being registered is a one unit signal, the first pulse will flow through conductor 390 and register the signal. If one added unit is desired, relay can be made inoperative, and relay 34 left operative as shown.

Assuming that the operation already described was done in registering the space pulse of the preceding signal on the tape, and that the tape as shown in the drawing has just been moved forward as described, the transmission of the signal indicated on the tape will be as follows: Mark needle 357 will rise through mark perforation 351 and engage its associated contact. The armatures of the timing relays are already reset and resting against their left hand stops. The first pulse of vibrator current will set timing relay 33; timing relays 34, 35, 36 following on the second, third and fourth pulses, respectively. The fifth pulse will flow through conductor 392 to the contact point associated with mark needle 357, thence to conductor 3100 through needle 357 conductor 360 and needle 354, thence through coil 3101 of relay 399, coil 3103 of relay 398 and, from the point 3120, through the same path to battery lead as described for the space pulse action. The armatures of relays 399 and 398 will move in the direction shown by the arrows on the coils that are thus energized, and will consequently reassume the positions shown in the drawing. Reset relay 3111 will act again in the same manner as before, thereby resetting the timing relay armatures, and the apparatus will commence to register the space pulse of the signal-for which the operation has been described.

Describing nextthe apparatus shown in Fig. 8:

(6*, I), c, d, c" and f designate a group of six differentially wound polarized relays, serving as mark selecting relays. a is an extra dot, or signal lengthening relay, which serves the same purpose as timing relays 33 and 34 of the transmitting apparatus shown in Fig. 7 and I), c, d, e" and f operate to select one of six circuits through the typewriter units. This group of relays set, one after the other, on a series of current pulses, the same as do the timing relays of the transmitter, the contact points that close the setting circuits fcr the next succeeding relays in the described order being 9 of relay a, h of relay 6*, 2' of relay 0-, j" of relay d and 7c of relay e. The armatures of relays 6*, 0", rl" and e have insulated contact tips, as indicated at insulation 1 of the armature of relay 5*. This group controls the selection of paths through the typewriter magnet units, as follows: Battery lead 922/ is applied to conductor a when the armature of relay 6* engages contact 0*; it is applied to conductor p when relay Zr has set, or moved its armature into engagement with contact 9 and before relay 0* has set; and in the same manner the conductores r, s, t and u are selected and connected with battery lead m" according to the number of relays set.

21*, w, m, y", .2 42 and 43 designate a similar group of seven space selecting relays, for selecting one of the six typewriter circuits 44, 45, 46, 47, 48 and 49 and connecting it with battery lead 410, accordingly as relays 12*, 10*, at y, a, 42 and 43 set on the first, second, third, fourth, fifth and sixth pulses, respectively; relay 1; being an extra dot, or signal lengthening relay.

411 designates a vibrator controlling the setting of the space selecting relays through the battery 412, conductor 413, contact 414, resistance 415, and the leads 416 and 417 across which the space selecting relays are connected in multiple in the manner described for the timing relays of the transmitter, and across which pulse regulating relay 418 is also connected through the circuit comprising resistance 419, conductor 420,the coil of magnet 421 and conductor 422 for applying the shunts comprising conductor 423, armature 424 and contact 425, and conductor 423, armature 424, contact 426 and conductor 427 around the space selecting relays in the manner described for the same class relay of the transmitting apparatus.

428 designates a vibrator, controlling the setting of the mark group of selecting relays through the battery 412, conductors 413 and 429, contact 430, conductor 431, contact 432, contact strip 433, conductor 434, resistance 435 and the leads 436 and 417 across which the mark selecting relays and the pulse regulating relay 437 are connected in the same manner as the similar space apparatus is connected across the space leads 416 and 417.

438 designates a polarized relay whose purpose is to eliminate the first pulse of current to the mark selecting relays each time marl: vibrator 428 is released to vibrate, which is accomplished by the opening ot' the circuit of the lead 436 at the contacts and 433; and to open the typewriter battery circuit after the first contact has been. made by mark vibrator 428, which is accomplished in connection with other apparatus by the disengaging of its armature 439 from contact 440. The armature 439 is insulated at 441 to separate the two mentioned circuits.

442 designates a relay controlling the typewriter battery 443, through its armature 444 and front contact 445.

446 designates the armature ot the receiving relay of the set, which is assumed to be controlled by a transmitting apparatus at a distant station, through a channel 4446 and a relay 4446 which is returned by a spring 4446. It controls, through battery 447, two local circuits, the first comprising back contact 4-18 of the receiving relay, conductor 449, the coil of magnet 450 of mark vibrator 428, conductor 451, the coil of magnet o't polarized relay 438 and conductors and 454, and the second comprising 'i'front contact of the receiving relay, con- "6, the coil of magnet 457 of space vibrator 411, conductor 458, the coil of magnet 459 of relay 442 and conductors 460 and one of these circuits being active and the other open accordingly as this armature engages one or the other of its contacts un der the control of the mark and space pulses of current or nin over the channel from the sendi When the former circuit st. 1 is closed, the armature of relay 438 is moved against contact 440; and magnet 4 0 of mark vibrator 428 draws vibrator rod 461 against step 462, thereby bending the normally straight vibrating spring 463 as shown in the drawing to give it sufi'icient potential energy to vibrate of its own elasticity on and contact 436 for a sufficient number ot' cycles, when released the magnet 45 energized, and bends the spring 465 in the same manner as the spring 463 was bent. The magnet 459 being energized pulls the armature 444 so as to move into engagement with the contact point 445. The armature of relay 438, after being moved against contact 440 by the energizing of its magnet 452, remains in that position when its coil is decnergized-held by the permanent magnetism or the r.ela ,-until it is moved back to contact 432 by outside means.

466 designates, in skeleton form, the principle and circuits of the receiving typewriter, comprising 436 units. similar to unit 467 which comprises the soft iron cores 468 and 469 which are connected by soft iron yoke piece 470, these cores being wound with coils 471 and 472, respectively, in series and in a direction to induce opposite magnetic poles at the free ends of these cores; the soft iron core 473, fixed to the yoke piece midway between the other two cores, wound with coil 474 and supporting, or being near, at its free end the soft iron armature 47 5, which is pivoted at 476 just above the "tree pole of core 473 with its free ends equally distant from both outside pole pieces when the armature is in the open position; and the spring 477 for moving the armature upward. 478 is a connecting rod between the armature and the type bar 479; the latter being pivoted at the point 480. Vihen current flows through the outside coils 471 and 472 only, the outside cores attract the armature 475 equally at both its ends, when it is in the open position, and cause no movement of the armature. When current flows through the center coil only, it likewise causes no movement of the armature, for the same reason. But, when both sets of coils are sin'iultaneously energized the device operates in the well under stood manner of a polarized relay, the center coil polarizing the armature, adding to the magnetism in the core 468 and detracting from the magnetism in core 469; and armature 5 will then be drawn down towards core 468, causing the type bar 479 to move up at its free end and imprint its character in the manner common to typewriters. The unit 480 represents the theory of the control of the functions of the typewriter, such as carriage return, line spacing, etc. It is similar to unit 467, except that it acts as a relay controlling through its armature 481 and front contact 482 the electromagnets which perform said functions. The other 434 skeleton units represent units of similar construction, the desired number operating individual type bars and the remainder serving as relays, controlling the functions. The arrangement in the drawing of sir: horizontal rows and six vertical rows of 81X units each is merely for the purpose or illustratthe connections and circuits, which are follows: Conductor a connects with the Each unit is upper horizontal row at the point 483 and current from battery lead m passes through all the outside coils of the six units in this row, in series, and flows to common battery return 484 at the point 485, when the mark selecting group of relays have selected this path; when conductor p has been selected the path includes the outside coils of the six units in the second horizontal row from the top, and connects with the battery return lead 484 at the point when conductor 9" has been selected the path includes the ,imilar coils of the third horizontal row and connects with battery return 484 at the point 487 when the conductor 8* has been selected the path includes the si .lar coils of the fourth horizontal row and connects with the battery return 484 at the point- 488; when conductor 1' 1 been selected the path nas includes the similar coils of the fifth horizontal row and connects with the return 484 at the point 489, and when conductor a has been selected the path includes the similar coils of the sixth horizontal row and connects with the return 484 at the point 490 In a similar manner the inside coils of the six units comprising the first vertical row at the le" as connected in series between the conductor ad the common battery return 491; the similar coils of the second vertical row between the conductor 45 and the same return, and the conductors 46, 47, 48 and 49 connect the similar coils of the third, fourth, fifth and sixth vertical rows, respectively, with the same return in the same mannerthe conductors 44, 45, 46, 47, 48 49 being selected and connected with the battery lead 410 by the space group of selcctin relays, as explained. When the iypcw iter battery is applied it flows simultzmeonsly through one of the vertical rows, o the path that has been selected roup of space selecting relays, and through one of the horizontal rows, accord to the path that has been selected by the up of? mark selecting relays; and it is v dent that one unit, and only one, will be nergizec thereby in both its outside and intide coils, That articular unit will operate: and other uni through which the current passes, will remain inoperative on account of being energized in only one set of coils.

492 designates a delayed action device whose pu pose is discontinue the application of the typewriter iattery after the proper interval of application. Its magnet 497 is energized simultaneously with the typewriter units 466, through the local circuit comprising typewriter battery 443, armature 444 and front contact 445 of relay 442, conductor 493, armature 439 and conact 440 of relay 438, conductors 494 and and twojoint paths, one of which comprises battery lead m and one of the mark selecting relay paths through a horizontal row of typewriter units 466 to battery return 484 and the other of which comprises battery lead 410 and one of the space selecting relay paths through a vertical row of typewriter units to battery return 491, and conductor 496. When energized, this magnet draws the armature 498 over against front stop 499. The inertia of the rod 4100 and weight 4101, supported by the vibrating spring 4102 which is rigidly fixed to the armature as shown in the drawing, causes the rod to lag behind the armature in this movement for an interval, the length of which is regulated by the position of the slidable weight 4101 upon the rod; and the rod then moves in the direction ot the armature travel under the force of the bent spring 4102 which tends to return to its normal straightness. The apparatus is adjusted so that the tip 4103 of rod 4100 strikes the tip of armature 439 of relay 438 just after mark vibrator 428 has engaged its contact 430 on the first cycle after being released to vibrate. This allows the following action to occur at the commencement of a mark pulse of a signal and while the delayed. action device .s completing this movement: Mark vibrator 428 makes one cycle that does not register on the mark selecting relays on account of the lead being open at the contact 432 and strip 433 of relay 438and the typewriter battery 443 is applied to the typewriter during this interval. hen tip 4103 of rod 4100 strikes the tip of armature 439 of relay 438, after this action has occurred, it moves armature 439 over against contact 432, thereby closing the circuit of mark vibrator battery lead 430 to vibrator contact 430, and'opcns the typewriter battery circuit at the contact 440 of relay at the same time applying a reset pulse from the typewriter battery 443 to the reset coils of all the selectin relays of the two groups, through the local circuit comprising battery 443, armature 444 and contact 445 ot relay 442, conductor 49?, armature 439 of. relay 438, tip 4103, rod 4101, spring 4102 and armature 498 of delayed action device 492, conductor 4104 (which includes in seres the reset coils of all the selecting reiays) to the point 4105 on conductor 496, and conductor 496 to the OpQOS iTO pole of the battery. The application oi this reset pulse lasts during the time tip 4103 ot rod 4100 remains in contact w'th armature of relay 438 in torcing it from contact 410 to contact 432. Magnet 497 of device 492 loses its magnetism when the armature of relay 438 leaves con-. tact point 440 and allows armature 498 to move to its back stop 4106 under the pull of its spring. The upper part of the device completes the movement ot armature 439 to contact 432 by its own inertia and then swings back and comes to rest against vibration absorber 4107. The latter comprises a weight, loosely pivoted at the point 4108. The foregoing operation of this device occurs while battery relay 442 is energized and is holding its armature 444 against front contact 445.

The operation of this apparatus may be briefly described as follows: Contacts 430 and 414 of vibrators 428 and 411 are adjusted so that they just clear tie contact springs of their respective vibrator rods when vibrator springs and 465 are in their normal position oi straightnessas dicated by the position of vibrator spring 465 in the drawing. The slidable weights are adjusted upon the vibrator rods to make the rate of vibration the same as that of the vibrator at the transmitting station. Delayed action device 492 is adjusted as explained. Polarized relay 438 and all the polarized relays of the two groups or selecting relays are centered so that their armatures will rest against either stop when their respective coils are not energized, and pulse regulating relays 418 and 43? are adjusted so that the proper length pulse will pass to the selecting relays.

The position of the apparatus in the drawing, except that of the mark selecting relays, is the same as it should be just after line relay armature 446 has moved from front contact 455 (at the completion of the mark pulse of a signal) into engagement With back contact 448 (to register the space pulse of the same signal). Mark vibrator 428 has just been drawn over against stop 462; polar relay 438 has just moved its armature into engagement with contact point 440; relay 42 has just opened, and magnet 45. of space vibrator 41.1 has just released the vibrator rod from engagement with stop 464. To follow out the assumption that the mark pulse of? the signal 1 am describing has just been registered, 1 will assume that mark selecting relays a 23*, and 0 have been set by this assumed mark pulse, and that their armatures are resting against the contacts 9, 7L and 2', respectively; and that the signal being registered is the alphabetical signal comprising three mark .and six space units, with one unit added to compensate for retardation.

The vibrator 411. r will vibrate on and oil c ,atact 414 as ion 3 as line armature 446 remains against back contact 448. As the space pulse coming over the line from e sending station is 41 units in length, accoi to the relat ve l vibrators, vibrator act 414 seven ti -J pulses of on 416 and 417; ind space selecting re -Js '0 w, m, y, 2*, 42 and will accordingly set on the first. second, third, "fourth. tii'th, sixth and seventh pulses respectii-ely, theirv connecting the typewriter battery lead A) with the sixth ertical row of typewriter units 466 from the left, through the tip 4168 of the armature of relay 11' contact 116 of the same relay, conductor 4111, armati 4112 and contact 4i 3 of relay y, cond 'urc lip 41 o and contact lay e", conductor 411i", a'i'n'iziture ti and contact 4-119" of ielay 42 armature 4121 and contact 4 and conductor 49.

Having rcgisterc: nianne' armatu contac J under t.

4120. oi relay 48,

' space pulse in this is moved against control oi the transranuzucncc the mark "giial and ti e followin due to the opening oi the ture and contact ill be released by its ina nct and connnence its vibrations on and Oil contact 430; the rod of space vibrator 411 will drawn over into engagement with stop 464 and be made inoperative (being attracted by its magnet at the point in one of its swings where it is nearest to the magnet, as ii; was from this relative position that it commenced its vibrations) and relay 442 will close, thereby applying the typewriter battery 443 to the typewriter units 466 through the magnet coil of delayed action device The armature of relay 438 will remain against contact 440.

The typewriter battery, applied by the closing of relay 42, flows through front contact i of that y and over the described flltla'. through the arn'iature and contact 440 of relay and through the coil of magnet 45)? of delayed action dovic. to pewriter batten. lead 410, which is now connected wi h the conductor 49 at contact 4122 oi space selecting relay 4 and thence through the center coils of the six units comprising the sixth vertical row of typewriter units from the left to battery return 491, and thence to the opposite pole of the battery through the conductor 4%. Simultaneously, it flows through battery lead 7224, from conductor 495, to the tip or the armature of mark selecting relay 6; and thence through the particular horizontal row oi typewriter units that were selected by the mark selecting relays in registering the mark pulse of the signal being described (which pulse was assumed o have set the mark selectii relays a", b". {iii .1 1*). The path of the current from tip o the arn'iature of relay 72 back to 1019 of the battery would be. contact of relay conduc- 4124 and contact 4125 of relay 4126., armature tip 412'? and of relay (5, conductor 1", the

lilarl' vibrator w 0 controlled by this armature and ltlll outside coils of the six typewriter units comprising the third horizontal row from the top to the point 437 on battery return and .conductor 496. Typewriter unit 4128 which is included in both the vertical and horizontal rows that are thus energized, will operate as described. Delayed action device 492 will operate in the manner explained during the application of the typewriter current, forcing armature 439 of polar relay 438 over against contact 432thereby opening the typewriter battery circuit at the contact 440 and momentarily applying the reset current through the reset coils of the selecting relays of both groups.

As before stated, the delayed action device is adjusted so that the vibrator 428 will have made one engagement with its contact 430 that does not register on the mark selecting relays on account of armature 439 of relay 438 being out of engagement with contact 432. To compensate for this, the mark selecting relays are normally in position, when reset, to select the path through the typewriter units that represents one mark unit; and the mark group of selecting relays accordingly contains one less relay than the space group.

If no lengthening of the signals is desired, mark selecting relay and space selecting relay 0/ can be made inoperative, as explained in connection with the similar relays of the transmitter. The above described signal will then register through the same typewriter unit, as one less dot in both mark and space pulses will have been transmitted from the sending station for the signal. Greater lengthening of signals can be obtained by adding more extra dot relays to the mark and space selecting groups, one to each group for each extra dot desired.

Describing next the apparatus shown in Figure 9:

a and Z2 designate the sending and receiving wheels, respectively, of a multiplex system, connected by the line wire 0 through the stationary brushes (l and 6 They are assumed to be synchronized by some approved method not connected with my invention, so that when the wheels are revolving, the insulated metal sending segments f 9 71 2' 7' and k of Wheel a maintain true relative positions with the corresponding receiving segments Z, m of, 0 p andp, respectively, of wheel 5 thereby connecting each receiving segment to the line through the brush 6 during the time its corresponding sending segment is passing under brush (1 in the usual manner.

r designates, in skeleton form, a transmitting set similar to the apparatus described in Figure 7 except that the vibrator and the pulse regulating relay (0? and s of Fig. 7), are replaced by the stationary brush 8 and the metal strip t, the latter being carried on, and insulated from, the face of the wheel. Strip makes contact with brush 8 as the former passes beneath the latter. thereby putting a pulse of current into the timing relay battery leads a and o (1 and k of Fig. 7), through the local circuit comprising battery to conductor .72, brush s strip i conductor a timing relays 3/ 2", 52, 53, 54 and 55 and conductors 513 and 514, once every revolution of the wheel a. The dura tion of the pulses may be regulated by moving brush 8 toward or from the axle of wheel a, as is apparent. The remaining apparatus of the sending set, being similar, is omitted except that line transmitter 56 (polarized relay 399 of Fig. 7) is shown to illustrate the main line transmitting connections, which are as follows: lVhen armature 57 of this relay engages contact 58 it applies battery 59 to sending segment 7 of wheel a through conductor 510, and when it engages contact 511 it applies the opposite and equal battery 512 to the same segmentthe combination forming a polar transmission similar to that employed in apolar duplex.

515 designates a similar transmitting set, connected to sending segment 72 by conductor 516 and receiving pulse currents for the operation of its timing relays, etc., through strip 517, conductor 518, timing relays 519, 520, 521, 522, 523 and 524, conductors 525 and 514, battery 10 conductor ac and brush s-"the brush 8 and pulse battery w being common to both transmitting sets.

526 designates, in skeleton form, a receiving set similar to the apparatus shown in Fig. 8, except that the vibrators 428 and 411 and the pulse regulating relays 437 and 418 of that drawing are replaced by stationary brush 527, metal strip 528 and polarized relay 529. The latter operates to close the pulse circuit through the mark selecting relays 530, 531, 532, 533, 534 and 535 when armature 536 engages contact 537 and to close the pulse circuit through the space select-ing relays 538, 539, 540, 541, 542 and 543 when armature 536 engages contact 544, through the local circuit comprising common battery leads 545 and 546, common pulse battery 547, conductor 548, brush 527-, strip 528, conductor 549, armature 536, and one or the other of the relay contact points and connected group of selecting relays. The remainder of the set, being similar, is omitted, except line relay 550 which designates a polarized relay, the armature 551 and contacts 552 and 553 of which rep resent line armature 446 and associated contacts 448 and 455, of Fig. 8. This relay is connected between receiving segment Z and the ground by conductors 554 and 555, the coil of magnet 556 of relay 529 and conductor 557.

558 designates a similar receiving set, conill) nected to receiving segment g and receiving its pulse current from common pulse battery 5 17, through strip 559, in the manner described for set 526brush and battery 547 being common to both sets.

The operation of this apparatus is as follows: When armature 7 of line transmitting relay of sending set 1 rests against contact 11 it applies battery 12 to line 0 when segment is passing beneath brush (Z and, as segment Z of wheel 5 passes beneath brush a at the same instant, this battery lows from line 0 to segment Z through brush 6 and thence to the ground through conductor st, the coils of relays 550 and 529 and conductor 557, causing relays 550 and 529 to move their armatures into engagement with contacts 553 and 537, respectively. When armature 57 rests against contact 58 it applies opposite battery 59 to the channel in the same manner, which causes the armatures of receiving relays 550 and 529 to move in the opposite direction and engage contacts and 14, respectively. When segment Z is out of engagement with brush eduring the greater part of each revolution of wheel Z) the armatures of polarized relays 550 and 529 remain as positioned by the last contact of this segment and brush, due to the holding force of the permanent magnetism oi? the relays.

The pulse currents that operate the transmitter are made effective when sending segment 7 is one half of a revolution beyond line brush (Z, and its associated contact strip 25 is passing beneath brush 8, consequently, the movements of armature 7 of line transmitting relay 56 from one contact to the other, which occur only while a pulse current is effective, will be made only when this segment is half a revolution beyond line brush (Z and no changes of applied current can occur in segment f while it is passing under line brush d.

At the receiving end, the pulse currents that operate the receiving apparatus are likewise effective one half of a revolution of wheel 5 after segment Z passes line brush a. It the sending and receiving wheels are in perfect synchronism the pulses will be eifectivc at identical and precise intervals after any movement of the armatures of receiving relays 50 and 29 which can occur only at the instant segment Z is passing beneath brush 6.

The operation of sending set 15 and its associated receiving set 58 through sending and receiving segments and (7, respectively and that of four other similar sending and receiving sets that may be used on the wheels shown in the drawing), will be similar to that of the sets and channel described.

Describing next the apparatus shown in Fig. 10.

a designates a selecting device through which he perforated tape shown in Fig. 5 is aut matically fed, comprising first, second rd clement selecting needles 5, 0, and i ely, which are similar to the shown in 7 except that they are positioned above tape 0 and engage the perforations therein, as f under the downward push oi compression springs g, h and '5; contacts j, 7; and Z, associated with the needles Z), and (Z respectively; needle controlling lever m, positionec to engage projecting knobs m 0 and p of the selecting needles from the under side; sprocket wheel (7 for moving the tape forward and lever 1 for controlling needle lever at through its extensions 3 and for turning sprocket wheel (7 through lever 25 which. is pivoted on the free end of lever r and extends up behind the sprocket wheel where it engages the teeth of the wheel under the pull of spring a in the usual manner. Magnet 0 and spring w control the n'iovement of lever 7* between stops m and 7 the coil of this magnet being included in the local circuit comprising conductor .2, the coil of magnet 2 of vibrator 3, conductor 4, battery 5, conductor 6, vibrator 3. contact 7 and conductor 8.

9 and 10 designate two polarized relays, controlled by the selecting needles and their associated contact points as follows: hen needle Z) is moved downward through a perforation in the tape, as shown in the draw ing, it closes the local circuit through coil 611 of relay 616 and coil 612 of relay 69, comprising battery 613. conductor 38, contact 7". needle 7). conductor 614, coil 611, conductor 615i coil 612 and conductor 616: when needle 0" engages a perforation it closes the local circuit comprising battery 617, conductor 61S. needle c, contact 7:, conductor 619. coil 620 or relay 10. conductor 21. coil 22 of relay 9 and conductor 23 and when needle (Z engages a perforation it closes the local circuit comprising battery 624" conductor 625. needle (Z contact Z, conductor 626. coil 627 oi relay 610 and conductor 628. The coils of these two relays. when energized, cause the movements of their respective armatures in the directions indicated by the a1"ows on the coils; causingarmature 629 of relay 610 to connect line wire 630 with the ground through contact 631 when third element needle a? enters a perforation: causing armature 629 of relay 610 to connect line wire 630 with the armature of relay 69 and thence to negative battery through contact 632 of relay 610, conductor 633 and contact 636 of relay 9, when second element needle 0 enters a perforation and causing armature 629 of relay 610 to connect line wire 630 with positive battery through contact 632 of relay 610. conductor and the armature and contact 637 of relay 69s when first element needle 5 enters a perforation.

n Go 

